Method of joining pipes



; Nov. 14, 1933. I w. H. ARMACOST I 1,935,041

METHOD OF JOI NING PIPES Filed March 12, 1930 2 Sheets-Sheet 1 5m"firmacaff" 11v VENTOR A TTORNEY Now 14, 1933. H ARMA QST 1,935,041

METHOD OF JOINING PIPES Filed March 12, 1930 2 Sheet s-Sheet 2 A TTORNEYPatented Nov. 14, 1933 METHODOF JOINING PIPES Wilbur H. Armacost, NewYork, N. Y., assignor to The Superheater, Company, New York,

v Application March 12, 1930. Serial No. 435,201

2 Claims.

The present invention relates to a process for joining pipes by means ofautogenous welding and has for its purpose the provision of an improvedmethod of this kind.

' In case the end of the first pipe opposite the joints of pipes can bemade, but no satisfactorymethod has yet been suggested for testingjoints after they have beenmade so that it is never certain whether thewelder has done his work thoroughly or not. Joints of this type wouldundoubtedlyjcome into more general use if a method could be devised fortesting the joint, or if some other way could be devised for assuringthe user of the safety of the joint. The latter is what my invention isintended to do.

I illustrate my invention on the accompanying two sheets of drawings inwhich Figs. 1, 2 and 3 illustrate successive steps in the process, thepipes being shown either entirely or partly in longitudinal section, andFig. 4 shows the completed product. Fig. 5 shows the completed jointembodying a variation, and Figs. 6, '7 and 8 illustrate steps inreassembling the joint after it has been broken. Fig. 9 shows avariation of the invention.

Referring first to Fig. 1, the two pipes to be joined are shown at 1 and2, their ends are upset or thickened as at 3 and 4, the interiordiameter being kept unaltered. A machine thread 5 is cut on one upsetend.- A correspondingly threaded sleeve 6 is screwed on the threaded end3 or slipped on the pipe from the opposite end of the pipe if this isaccessible. The two pipes 1 and 2 are then brought into the relativepositions they are to occupy with their s'carfed ends 7 and 8 injuxtaposition. The upset end 4, it will be noted, is unthreaded at thisstage. The two pipes are so held in the position indicated and welded asat 9,

Fig. 2, in the ordinary way, the added material.

for the weld being built up so as to extend at least as high all aroundas the upset ends 3 and 4. Asplit die is next put in place on the thread5, and a thread is cut on thematerial 9 and the upset end 4, asindicated at 10 and 11 in Fig. 3.

The die is then removed and the sleeve 6 screwed into .place asindicated in Fig.4.

This .completed pipe joint depends primarily for its strength upon theweld 9 but the sleeve 6 will if necessary. take up any stresses. Inorderv to keep the sleeve in place and not permit itscareless removal itis preferably 'welde'd at one or two points to one of the pipes asindicated at 12. 53

It will be understood that the amount to which the pipes have to beupset does not need to be very great. There must be provided merelyenough thickness so that the threads 5 and 1 1 do not weaken the pipeends below the strength of the pipes themselves.

In some instances 'instead of upsetting the pipes, a belling out, asindicated in Fig. 5, will be entirely satisfactory. The belling out iscarried only to such an extent that the threaded sleeve 6 76 can bescrewed backon to the pipes.

Provision must be made in someinstances for breaking and remaking such apipe joint. If the sleeve is screwed off and the welding materialremoved, thereby separating the pipes, it would ordinarily be verydiflicult to get them back into the original relative position for thepurpose of rewelding them, and unless they'were replaced in the originalrelative position the sleeve could not be screwed into place. I providefor such 30 breaking and remaking of the joint by forming the sleeve 6with an aperture indicated at 13. Its use is as follows: When the pipeshave been separated and are'to be reconnected, the material that wasoriginally added in making the first joint is removed so' that the pipesare again beveled'at their ends. They are then placed into the originalrelative position and the sleeve 6 screwed into place. At three or fourpoints on the circumference the two are then spot welded together as at14, Figs. 6 and 7. The sleeve is then screwed back out of place, the twopipes being held in their relative positions by the spot welding. Afterthis the weld is completed in the ordinary way. The material added maybebuilt up beyond the contour of the pipes just as in "the original weld,in which case a split die has to again be used to cut a new thread inthis ma terial; or the material is not built up quite as high so that itis unnecessary to out such a thread. The latter idea .is illustrated inFig. 8 where it will be noted the material 15 does not quite fill the Vshaped space between the two pipe ends. I

After the weld is finished the sleeve is screwed 1 into place and tackwelded in position as at 12.

It will be clear that some variations may be made in practicing myinvention, without departing from its spirit.

It is not necessary that the connection between r the sleeve and thepipes be efiected by threading one on the other. Different means may beused, as illustrated in Fig.9, where the sleeve 6 is secured to thepipes 1 and 2 by means of the dowels 16. The manner in which theassembly is made is obvious. If desired, the ends of the pipes may beupset in which case the number of dowels required will be less. Thedowels are distributed around the sleeve and may or may not extendthrough the pipes. If they do, their outer ends should be sealed up bywelding.

This form shares some of the advantages or the form first described butit is more difficult to take down and reassemble thejoint. To do this,the dowels have to be drilled out, and temporary dowels inserted fortacking together the pipes preparatory to welding them together. Thetemporary dowels are then withdrawn, the sleeve pushed out of the way,the welding performed, the sleeve replaced, and the permanent dowelsinserted.

I claim:

1. The method of joining two pipes comprising enlarging the externaldiameter of the pipes adjacent to their ends, cutting a. thread on oneof the enlarged ends, placing a threaded sleeve on the threaded endclear of the threads, welding the ends together, completing the threadover' the weld and over the second enlarged end, and screwing the sleeveon to engage both ends.

2. The method of joining two pipes comprising enlarging the externaldiameter of the pipes adjacent to their ends, cutting a thread over eachof the enlarged ends, placing a threaded sleeve on'one of the pipesclear of the enlarged end, welding the ends together, and screwing thesleeve on to engage both ends, at least one of the together.

WILBUR H. ARMACOST.

CERTlFlGATE or CORRECTION.

Patent No. 1,935,041.

November M, 1933.

WlLBUR H. ARMA'GOST.

ltis hereby certified that error appears in the printed specification ofthe above numbered patent requiring correction as follows: Page i,strike outthe paragraph comprising lines 5 to 10 inclusive, and insertthe same after line 53, of same page; and that the said Letters Patentshould be read with this correction therein that the same may conform tothe record of the case in the Patent Office.

Signed and sealed this 23rd day of January, A. D. .1934.

(Seal) F. M. Hopkins Acting Commissioner of Patents.

threads being out after the pipes are welded

